1. Field of the Invention
This invention relates to an improved coffee machine and coffee-brewing system.
More particularly, the invention relates to an improved coffee machine and coffee-brewing system utilizing pods of compressed ground coffee.
Still more specifically, the invention relates to a coffee machine and coffee brewing system wherein the cooperation of special structural features of the machine with prescribed characteristics of the respective coffee pods results in a coffee beverage of unvarying quality.
2. The Prior Art
Coffee machines are known in a wide variety of types and work according to various operating principles. The present invention is concerned with machines wherein hot water is caused to pass through ground coffee, and in particular the type wherein the water passes through a water-permeable pod of ground coffee (tea-bag like, but compacted under pressure).
Coffee machines of the type using such pods (hereinafter called "pod" for simplicity) are known from e.g. U.S. Pat. Nos. 3,327,613 and 3,370,523. What is not known from the prior art is a machine wherein the characteristics of the coffee extracting chamber housing the pod during brewing (hereinafter called "the extracting chamber") are coordinated with specified characteristics of the pods themselves and of the coffee filter through which the beverage must pass.
The only relationship between these aspects, which is known from the prior art, is an empirical one. As a direct consequence of this the coffee beverage brewed with the prior-art machines,--even though their mechanical operation be satisfactory--will vary in taste and wholesomeness from brewing to brewing. In other words: the brewing results are not reliably reproducible and therefore not satisfactory.